1. Technical Field
The present invention relates to a metering valve. More particularly, the present invention relates to a metering valve applied to a gas powered nail gun which can assemble a gas cylinder.
2. Description of Related Art
Pneumatic nail gun is one indispensable tool for woodworking decoration, for driving nails into woods with the force from the compressed air. The conventional pneumatic nail gun is powered by high pressured air, which is necessarily equipped with an air compressor. The air compressor weights about from tens to hundreds kilograms. An air pipe is required to connect the air compressor with the pneumatic nail gun, but it occupies spaces and thus holds back the doceration.
In this regard, there is another gas powered nail gun powered by igniting gas. Such conventional gas powered nail gun uses gas from the gas cylinder as a fuel, and provides power by ignition and explosion which, can drive a needle in a striker firing action; that is, the gas powered nail gun has advantages of compact size, lightweight and portability, and does not need electricity. However, in the gas powered nail gun, the arrangement of a metering valve is perpendicular to the axial direction of the gas cylinder, such as the metering valve disclosed in U.S. Pat. No. 6,302,297. As such, the assembling direction of the adapter in the conventional gas powered nail gun is perpendicular to the axial direction of the gas cylinder, which is inconvenient for the user have to deliberately align the adapter with the gas cylinder in the installation.
To address the foregoing problem, another metering valve is provided in U.S. Pat. No. 6,419,168, in which the direction of the outlet of the metering valve and the axial direction of the gas cylinder are the same, so that the user needs not align the adapter with the gas cylinder during the installation of the gas cylinder, so as to eliminate the inconvenience. However, in the disclosure of the U.S. patent, the compression spring utilized in the metering valve is disposed under the sliding rod and connected to one end of the sliding rod. In this configuration the sliding rod, the spring and the gas cylinder are connected serially, such that the metering valve would has an excessive length which requires further improvements.